Fluorescent identification of axons, dendrites and soma of neuronal retinal ganglion cells with a genetic marker as a tool for facilitating the study of neurodegeneration

This study characterizes a fluorescent Slc17a6-tdTomato neuronal reporter mouse line offering strong labeling in axons throughout the optic nerve, dendrites and soma in 99% of retinal ganglion cells (RGCs). The model facilitates neuronal assessment ex vivo with wholemounts quantified to show neurodegeneration following optic nerve crush or elevated IOP as related to glaucoma, in vitro with robust Ca2+ responses to P2X7 receptor stimulation in neuronal cultures, and in vivo using a confocal scanning laser ophthalmoscope (cSLO). While the tdTomato signal showed strong overlap with RGC markers, BRN3A and RBPMS, there was no cross-labeling of displaced amacrine cells in the ganglion cell layer. Controls indicated no impact of Slc17a6-tdTomato expression on light-dependent neuronal function, as determined with a microelectrode array (MEA), or on structure, as measured with optical coherence tomography (OCT). In summary, this novel neuronal reporter mouse model offers an effective means to increase the efficiency for real-time, specific visualization of retinal ganglion cells. It holds substantial promise for enhancing our understanding of RGC pathology in glaucoma and other diseases of the optic nerve, and could facilitate the screening of targeted therapeutic interventions for neurodegeneration. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=140 SRC="FIGDIR/small/599589v1_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@13db8dforg.highwire.dtl.DTLVardef@1345f10org.highwire.dtl.DTLVardef@14d34e1org.highwire.dtl.DTLVardef@1cacb87_HPS_FORMAT_FIGEXP M_FIG Graphical abstract. Fluorescent identification of axons, dendrites and soma of neuronal retinal ganglion cells with a genetic marker as a tool for facilitating the study of neurodegeneration. Puttipong Sripinun, Wennan Lu, Sergei Nikonov, Suhani Patel, Sarah Hennessy, Claire H. Mitchell*. This study delves into a new mouse model, featuring a fluorescent Slc17a6-tdTomato neuronal reporter. This model effectively labels axons in the optic nerve, as well as dendrites and soma in 99% of retinal ganglion cells (RGCs). This allows for both in vitro and in vivo assessment of neurodegeneration, offering a practical tool for real-time, precise visualization of RGCs, with potential applications in various fields of neuroscience and neurology. Created by Biorender.com. C_FIG